A Synthetic Vision System (SVS) is a computer-mediated reality system. A SVS is commonly used in airborne systems to provide flight crews with clear, intuitive and unprecedented situational awareness of their flying environment by replacing a conventional sky and ground depiction on a Primary Flight Display (PFD) with a 3D representation of the external surrounding outside the aircraft. SVS combines a high resolution display, with data from precision databases that includes terrain and obstacle data, geo-political and hydrological data as well as other aeronautical information, data feeds from other aircraft and vehicles, and GPS technology to show pilots exactly where they are and how the aircraft is orientated.
An Enhanced Vision System (EVS) is a related technology which incorporates information from onboard sensors (such as, infrared (IR) cameras, near-infrared cameras, millimeter wave radar, multi-mode radar (MMR), LASER, etc.) to provide vision in limited visibility environments by overlaying the captured imagery on top of the synthesized imagery creating a Combined Vision System (CVS) which provides enhanced real time situational awareness. Obstacles such as terrain, structures, and vehicles or other aircraft on the runway that might not otherwise be seen are clearly visible with an IR/LASER/MMR image increasing the safety and the efficiency of terminal area operations.
The backbone of a Synthetic and Combined Vision System is an underlying detailed, high-resolution digital terrain and obstacle database. The terrain and obstacle database which originally found its application on the EGPWS (Enhanced Ground Proximity Warning Systems) has spawned off several related products and added unparalleled feature enhancements to existing products. Many of these innovations rely mostly on software to avoid the expense and difficulty of changing hardware in the cockpit at a time providing significant cost benefits to airlines. The SVS/EVS/CVS, the EGPWS, Synthetic Airport Moving Maps (AMM), Runway Awareness and Advisory System (RAAS) etc. are only a few innovative products which piggyback on terrain and obstacle databases.
The functioning, safety and operational benefits of the SVS, EVS, CVS, EGPWS, RAAS etc. are greatly dependent on the integrity and the completeness of the terrain and obstacle databases. Although current mechanisms for data procurement and building of terrain and obstacle databases perform a satisfactory job, they are cumbersome and involve a lot of manual intervention and processing. Once data is aggregated, it takes prolonged processing and distribution times. Limitations or challenges of current systems include; inaccurate terrain and obstacle databases that may lead to incidents and accidents, sensed data from onboard systems being leveraged for the current ownership flight mission but not used for other services, a longer update cycle of terrain and obstacle databases even though obstacles may be occurring more frequently, unregulated growth of obstacles and reporting mechanism, variety of obstacles growing over time while many aircrafts are not equipped with sense and avoid systems.